I really, really enjoy nonfiction graphic novels that are not memoirs. Specific enough for you?
As previously noted, a lot of graphic novel memoirs seriously bum me out; tops on this list were David Small's Stitches and Alison Bechdel's Fun Home. There's something about seeing challenging if not downright horrific childhoods and young adulthoods portrayed in pictures that I very nearly can't handle.
But history and biography graphic novels? Love 'em. Another good case in point of this phenomenon is Apostolos Doxiadis's and Christos Papdimitriou's graphic novel Logicomix: An Epic Search for Truth.* Although the authors admit the book is more "based on reality" than it is pure nonfiction (they provide a very nice note in the back, explaining how and when they deviated from pure fact), I decided it didn't really bother me. The book is a rather selective biography of the life of philosopher and logician Bertrand Russell, and covers the overlap between the philosophy of logic and the science of mathematics.
Now, I'm not saying I got a lot of it. I certainly don't get the math stuff and most of the logic stuff just seems like semantic wrangling to me, but I must say that the graphic novel format, for whatever reason, makes me feel like I've got a shot at understanding some of the basics of what the authors are trying to say.** Although I most likely won't have time to follow the interest, it also somewhat motivated me to maybe someday read more about Bertrand Russell--his is one of those names I hear a lot but can never really place. (Just so you know: he was born in 1872 in Great Britain, the grandson of former Prime Minister Lord John Russell, became a mathematical logician and well-known author, later became a vocal anti-nuclear activist, and died in 1970.) So thumbs up on this one; it ranks right up there with Jim Ottaviani's historical/scientific graphic novels Fallout and Suspended in Language: Niels Bohrs's Life, Discoveries, and the Century He Shaped.
*Can't remember where I heard about this one. Lesbrarian, did you suggest I read it? If so, thanks!
**I did learn this: I don't think you want to be married to a logician.